//: Playground - noun: a place where people can play

import UIKit

var greeting = "Hello, playground"
greeting = "张三"

print(greeting)

var dictionaryA = [1: 1, 2: 4, 3: 9, 4: 16]
var dictionaryB = dictionaryA

dictionaryA[4] = nil
dictionaryA
dictionaryB

let constantArray = [1, 2, 3, 4, 5]
